Sources said the family went to Syria in November, but did not stick together.

"The authorities believe the man joined the Jabhat Al-Nusra group and his stepson the IS (Islamic State).

"The wife worked as a cook while the daughter taught English to the children of the fighters in Syria," one source said.

The family members are believed to be in different parts of Syria as there are many militant factions.

One possible location is east Hama, where jihadists are known to have set up a base of operations

It is learnt that the authorities are keeping close tabs on the family.

The authorities are trying to find out how the family were influenced to go to Syria, and believe that the woman's former husband had something to do with their decision, according to sources.

In an exclusive, The Star had reported that five former Internal Security Act detainees are among 40 Malaysians who have joined IS militants.

The five named include 45-year-old former Kedah PAS Youth information chief Mohd Lotfi Ariffin, who was injured in an attack which killed the youngest Malaysian jihadist in Syria on Tuesday.

Twenty-one-year-old Mohammad Fadhlan Shahidi Mohammad Khir from Kedah was the second Malaysian jihadist to be killed in Syria.

In Putrajaya, Home Minister Datuk Seri Dr Ahmad Zahid Hamidi called on Malaysians to reject extremist views and protect the country's image.

He said the actions of a few individuals did not reflect the true nature of the country and its people.

"I don't have information on why they are involved in this kind of activity," Dr Ahmad Zahid said, alluding to the Malaysian jihadists.

"I was also once detained under the ISA but I have no intention of going to Syria or being involved in militant activities.

"We don't want Malaysia to be presumed internationally as a breeding ground for terrorists (and) we must protect the image of our religion and country based on the principle of moderation or wasatiyyah.

"This principle has to be defended by all citizens. We have to avoid being extreme left or extreme right."